Apparatus for the continuous formation of metal in sheets



J. F. JORDAN APPARATUS FOR THE CONTINUOUS FORMATION OF METAL IN SHEETSMarch 13,1951

2 Sheets-Sheet 1 Filed Oct. 27. 1949 March 13, 1951 J. F. JORDAN2,544,837

APPARATUS FOR THE CONTINUOUS FORMATION OF METAL m SHEETS Filed Oct. 27,1949 2 Sheets-Sheet 2 INVENTORz- W MOW Patented Mar. 13, 1951 UNITEDlisrAres PATENT oFFicE LAPP'ARATUS FOR THE CONTINUOUS FORMATION OF METAL"IN SHEETS James Fernanda Jordan, Huntington Park, Galif -assignorto'James Jordan Laboratory, Hunting tonrPark Calife, a partnershipApplication Gctober 27, 1949, Serial No; 123,960

2 Claims.

My invention -relatesto the-conversion of. a molten metal into sheets.

Numerous attempts have been made-to'continuously cast metal strip andmetal sheet." Two outstanding difficulties arose during these attempts:(1) product cleanliness, due to the oxidation of the formed product anddue toentrained slag and/or dross; and (2) the formati'onof the edges ofthe sheet proved troublesome. With'regards to the latter, when the sheetwas formedby dipping a revolving water-cooled drum into a bath of themolten metal, the molten metal lapped around the edges of the drum,resulting in the formation of a sort of channel, instead of thedesired.s m le sheet. formed channe solidified and shrunk,-the castproductbecame locked totherevolving' drum, resulting, in either ahot-tear-or in the impossible situation wherein the formed product couldnot be stripped off of the drum. a

My invention concerns an improved casting drum wherein the molten metalis prevented from lapping" around said drum by means of a barrier of gassituated atboth ends ofsaid drum.

Figure 1 shows my casting drum with said'barriers of gas in position. 7

Figure 2 shows one end of thedrum of Figure 1.

Figure 3 shows an arrangement of my drum, in combination with a dynamic.weir.

Figure 4 shows two of my drums, cooperating to produce one sheet.

In Figure 1, revolving water-cooled drum 9: is shown contacting moltenmetal -.bath,40, thereby continuously producing metal sheet ll. Saiddrum 9 is cooled by the circulating body of water 36 with whichitis-filled, said circulation being achieved as cold water B enters drum9* via the hollow drum-shaft -39 and the warmed water A leaves said drum9 viathehollow drumshaft'38. Casting face 8 is immersed beneath surfaceillA of molten metal bath- 40,'and' the molten metal in said bath 40 isprevented from lapping up around the ends of-saiddrum 9-by dynamic weirsl5 and I6. Weirs l5 and I6 are barriers of highvelocity gas which pressdown upon surface 40A to form an indentation in said surface 40A ofsufficient depth to exceed the depth to which casting surface 8 isimmersed beneath said surface 49A. Said indentations in said surface49A, being located at each end of said drum 9, prevent bath 40 fromlapping around said ends of drum 9, and thus prevent the formation ofsolidified metal on said ends of drum 9. As sheet ll forms and leavessaid drum 9, the level of surface 40A is maintained as bath 49 flowstowards said drum 9 along hearth l8.

Weirs l5 and I6 are formed by directing orifices I2 and I3 towards thejunctions of said surface 40A and said ends of drum 9. Said orifices l2and I3 are connected to a source of high-pressure As thegas (not shown);The pressure exerted by weirs I5 andl6 uponsurface 49A, and the depth ofthe resulting indentation in said surface 40A, may be varied by varyingthe'pressure of gas l0 against orifices i2 and" I3, or' by varying thedistances between said orifices l--2 and- I3. and s'aidsurface 49A;"li'h'e size of said indentatio'n may beincreased in area by increasingthe distances between said orifices and saidsurface MIA-followed byincreases in the pressure exerted by gas [0 against said orifices,orsaid area'of indentation may be increased by increasing the size(area) of said orifices-followed by increases in the pressure exertedby'gas it against said orifices. The area of indentation "must beatleast sufii'cient to adequately cover the area ofcontact'of' said drum 9with said surface 40Asee Figure 2.

The gas employed in saidweirs' i5 and It should be at least neutral tothe-metal being cast-that is, non-oxidizing. With steel, nitrogen,carbon monoxide and helium maybe employed; with copper, carbon" monoxideispreferred.

Figure 2 shows the drum of Figure 1, looking at one end of said drum 9.Refractory dam M is shown skimming'ofislag layer 17 as bath 49 is ledout of the casting apparatus by drum 2''.

The arrangement of Figure 3 does 'not'show the stripping drum-suchasdrum 45 in Figure 2-- although such a stripping drum will in mostcases be required. Figure '3' shows drum 3| in cross section, and,accordingly, does not'show the \veirs which are positioned at each endof said drum 3L Barrier ofgas 32 is an elongated column of gas that isimpinged towards molten metal bath 33 in order to block off slag layer34 from the casting operation, said barrier being caused to extendentirely across the bath of metal 33 that is flowing towards castingface 1. The

function of said barrier or" gas 32 is simply to dam slag layer 34. Saidbarrier is formed by orifice means 28 that passes thru roof 29 anddirects gas 26 towards bath 33. Gas 26 is supplied to said orifice means28 by a high-pressure source (not shown). Bath 33 is shown flowingtowards drum 3! on refractory hearth 35.

Figure 4 shows a further modification. Here, two casting drums 56 and 58are shown casting the metal of bath 5|, said drums 5B and 58 beingrotated in opposite directions in pressing contact with each other, sothat the two metal sheets which are formed at casting surfaces 5 and 6are pressed together at the point of contact between drums 56 and 58,said two cast sheets being welded together at said point of contact toform sheet 55 that leaves the casting apparatus by passing up thru roof41. Said drums 56 and 58 are rotated in opposite directions, each ofsaid drums being rotated in that direction which constitutes theshortest distance between each drums casting surface and the point ofpressing contact between said drums 56 and 58.

The pressing contact between the two casting drums 56 and 58 results inthe welding together of the two sheets to produce the single sheet 55,each of said drums 56 and 58 acting as a stripping roll for the otherdrum; furthermore, due to the fact that the surface of the sheet thatlies next to the casting surface will always be smoother than thesurface that lies away from said casting surface, the arrangement ofFigure 4 will produce a much smoother sheet than when only one castingdrum is being employedthe rough surface of each sheet being turned in toform the center of sheet 55.

As with Figure 2, Figure 4 shows the use of my barrier of gas 48 and 49at each end of both of the casting drums, said barriers 48 and 49 beingform d as orifices 51 and 59 direct gas l towards the junctions of thesurface of molten metal bath and said ends of drums 56 and 58, saidbarriers being caused to press said metal surface down at said drum endsuntil said surface is just equal to, or below, the depth of immersion ofcasting surfaces 5 and 6, so that molten metal 5| will not lap aroundsaid drum ends.

As with Figure 3, Figure 4 shows the use of another barrier of gas 50 tohold back slag layer 52, so that said layer 52 does not enter thecasting operation. Barrier 50 is formed by means 46 which is fed byhigh-pressure gas 54.

In the arrangement shown in Figure 3, three barriers of gas areacting-one at each end of drum 3% and one to hold back slag 34. InFigure 4, five barriers of gas are employedone at each end of eachcasting drum and one to hold back slag 52. When casting sheet steel, thehighpressure gas employed in these barriers of gas should be carbonmonoxide, 'for this gas will protect the surface of bath 5| and thenewlyformed sheet 55 from oxidation. Other nonoxidizing gases may beemployed in these barriers-nitrogen, argon, helium or a mixture of COand CO2, for example.

Gas barriers I5, l6 and 32 may be composed of a preheated gas if thecircumstances require; that is, if said barriers tend to cause themolten metal in baths 33 or 45 to solidify, said barriers 'may bepreheated sufficiently to prevent this solidifying action.

When casting a metal with strong shrinkage characteristics, castingfaces 5, 6, I and 8 should be slightly concave, so that when the castsheet draws in from the ends of the casting drum, the casting surfacewill offer no resistance to the movement of the relatively-weak sheet.The axis of said concavity of the casting face of the drum must beparallel to the direction of rotation of said drum.

The expression sheet, as employed in the claims, denotes metal sheet ormetal strip.

Having now described and shown several forms of my invention, I wish itto be understood that my invention is not to be limited to the specificform or arrangement of parts herein disclosed and shown, except insofaras such limitations are specified in the appended claims.

I claim as my invention:

1. In a continuous casting apparatus, a vessel adapted to hold a pool ofmolten metal, a casting drum rotatably mounted in said vessel with aportion of its circumference extending below the normal molten metallevel in said vessel, nozzles positioned above the molten metal and ateach end of the casting drum, said nozzles being directed so as to causea barrier of gas to press down into the surface of said molten metal ateach end of said casting drum and at the point where said molten metalcontacts said ends of said casting drum, and means for supplying saidnozzles with gas under suficient pressure to cause said barriers of gasto press down into the surface of said molten metal to a depth at leastequal to the depth of immersion of said casting drum in said moltenmetal, so that said molten metal is prevented from contacting andsolidifying on said ends of said casting drum.

2. The apparatus according to claim 1 in which the casting face of saidcasting drum is concave, so that the solidified metal may shrink incontact with said casting drum without gripping said casting drum.

JAMES FERNANDO JORDAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Duce May 3, 1949

